In the conventional manufacture of cigarettes, a tobacco filler rod is formed by moving an air-permeable collecting surface transverse to a vertically-moving thin shower of tobacco, collecting the tobacco thereon to build up a tobacco filler rod across the width of the shower, and wrapping a paper web around the tobacco filler rod. In general, two systems are in commercial use, one wherein the vertically-moving thin shower passes upwardly into engagement with the collecting tape and the other wherein the shower falls downwardly onto the collecting tape.
Upstream of the location of the vertically-moving thin shower a variety of structures and operations have been adopted to form a wide stream or carpet of tobacco from which the shower is formed. Cut tobacco is received by the cigarette-making machine onto a hopper and tobacco is manipulated within the machine by a variety of procedures to form the aforementioned wide carpet. In each of these procedures some form of metering of tobacco occurs, often combined with internal recycle of tobacco, which causes degradation of the tobacco and impairing of filling power. In addition, tobacco often is provided to the hopper in a somewhat unopened form as a result of the procedures used to convey tobacco from cutting operations to the cigarette-making machine, so that the metering operations often lead to further degradation of the tobacco.
One such prior art arrangement is the so-called Molins Mark IX machine. In such machine, following manipulation of the tobacco from the hopper to open it, tobacco is removed from the reservoir of such opened tobacco by a rotary carding drum as a wide stream of tobacco particles, the wide stream then is passed adjacent a second counter-rotating carding drum, which cooperates with the first carding drum to limit the quantity of tobacco in the wide stream by a refusing action.
Another such machine, the so-called Hauni Protos machine, tobacco is transported from a hopper by a lifting conveyor which has a metering device in the form of a refiner associated therewith. From the top of the lifting conveyor tobacco is fed to a downward chute onto the outer surface of a transport roller in the form of a carding drum. A picker roll then picks the tobacco from the surface of the transport roller onto the upper surface of a transport conveyor on which the tobacco is fed to a filler rod-forming mechanism.
In copending U.S. patent application No. 863,009 filed May 14, 1986, (now U.S. Pat. No. 4,754,765) assigned to the assignee hereof and the disclosure of which is incorporated herein by reference, there are described modifications to the Molins Mark IX machine and the Hauni Protos machine, wherein a novel hopper and transportation arrangement is provided which by-passes the internal hopper arrangement, introduces a wide stream of particles to the carding drum and the conveyor respectively which then act solely as transportation devices to rod formation. There is no internal tobacco recycle nor refuser operations, thereby avoiding the tobacco degradation that results therefrom.
In U.S. Pat. No. 4,459,999, also assigned to the assignee herein, the disclosure of which is incorporated herein by reference, there is described n cigarette-making operation wherein a reservoir of tobacco is metered and opened to form a tobacco feed stream from which a filler rod is directly formed.